Abstract: Systems and methods are provided for efficiently maintaining a transaction sequence witness service to ensure that requests to read data provide consistent results across all storage nodes in a distributed system. When a storage node receives a request for a data object, the node may obtain—from transaction sequence witness service—the latest sequence number associated with the object. If the sequence number indicates the object has been modified in the period of time since the currently stored version was stored, the node can obtain the current version from persistent storage.

Abstract: An object-based data storage service receives a request to store a data object in association with a smart data storage tier. Based at least in part on characteristics of the data object, the object-based data storage service identifies and stores the data object in a first location corresponding to a first data storage tier. The object-based data storage service monitors access to the data object to identify a second set of characteristics of the data object. This second set of characteristics is used to determine that the data object is to be transitioned to a second data storage tier. The object-based data storage service, based at least in part on this determination, stores the data object in a second location corresponding to the second data storage tier.

Abstract: Systems and methods are provided for managing data partitions in a distributed storage system and, in particular, the routing data used by the distributed storage system to route requests to the proper caching layers, persistent storage nodes, etc. Data items may be managed in a multi-tier configuration in which they are grouped into different partitions based on their key prefixes, and partitions are grouped into different cells based on key ranges. When partitions are moved from cell-to-cell, or when cells are split, the routing data is changed accordingly. In order to ensure that the correct routing data is used throughout the distributed storage system, a change to routing data may be accompanied by a special barrier record being written to the transaction log of affected partitions.

Abstract: Systems and methods are provided for managing the order of data written to a transaction log in a distributed storage system. In a system with multiple nodes, if sequencers are naively generated without taking into consideration inconsistencies among the different nodes generating the sequencers, then the sequencers may not increase for each data transaction. To alleviate this problem, the node committing the transaction to the transaction log may perform a consistent read and verifies that the sequencer advances. If the sequencer does not advance, the node can perform a context-dependent operation such as adjusting the sequencer, acknowledging the write without committing it to the transaction log, or rejecting the write altogether.

Abstract: An object-based data storage service receives a request to store a data object in association with a smart data storage tier. Based at least in part on characteristics of the data object, the object-based data storage service identifies and stores the data object in a first location corresponding to a first data storage tier. The object-based data storage service monitors access to the data object to identify a second set of characteristics of the data object. This second set of characteristics is used to determine that the data object is to be transitioned to a second data storage tier. The object-based data storage service, based at least in part on this determination, stores the data object in a second location corresponding to the second data storage tier.

Abstract: An object-based data storage service receives a request to store a data object in association with a smart data storage tier. Based at least in part on characteristics of the data object, the object-based data storage service identifies and stores the data object in a first location corresponding to a first data storage tier. The object-based data storage service monitors access to the data object to identify a second set of characteristics of the data object. This second set of characteristics is used to determine that the data object is to be transitioned to a second data storage tier. The object-based data storage service, based at least in part on this determination, stores the data object in a second location corresponding to the second data storage tier.

Abstract: A context management service provides historical context information describing the state of a computer system at a particular time to an event processing service. When an event is received by the event processing service, the event processing service determines, based at least in part on the event, a point in time for which context information is desired. The event processing service requests the desired context information from the context management service. The context management service produces a context snapshot that describes the state of the computer system at the determined point in time, and provides the context snapshot to the event processing service. The event processing service is able to use the context information to process the event in accordance with the state of the computer system at the determined point in time.

Abstract: An object-based data storage service receives a request to store a data object in association with a smart data storage tier. Based at least in part on characteristics of the data object, the object-based data storage service identifies and stores the data object in a first location corresponding to a first data storage tier. The object-based data storage service monitors access to the data object to identify a second set of characteristics of the data object. This second set of characteristics is used to determine that the data object is to be transitioned to a second data storage tier. The object-based data storage service, based at least in part on this determination, stores the data object in a second location corresponding to the second data storage tier.

Abstract: An object-based data storage service receives a request to store a data object in association with a smart data storage tier. Based at least in part on characteristics of the data object, the object-based data storage service identifies and stores the data object in a first location corresponding to a first data storage tier. The object-based data storage service monitors access to the data object to identify a second set of characteristics of the data object. This second set of characteristics is used to determine that the data object is to be transitioned to a second data storage tier. The object-based data storage service, based at least in part on this determination, stores the data object in a second location corresponding to the second data storage tier.

Abstract: Computing resource service providers provide computing resources to a plurality of customers. To avoid customers experiencing a degradation in service associated with the computing resources provided to customers, a main queue and a sideline queue may be used to manage and distribute customer events to service endpoints. Customer events may be placed in a main queue and transmitted, by a delivery host, to a service endpoint. If the delivery host receives a throttle response from the service endpoint, the delivery host may enqueue the customer event in a sideline queue and generate and/or store state information associated with the customer event. The state information may include an interval of time at the expiration of which the customer event may be retransmitted to the service endpoint.